The UHF channel 36 allocation was originally assigned to Stockton, and was occupied by a short-lived UHF station under the callsign KTVU (not related to the present-day Oakland-based sister station of KICU) that existed in the mid-1950s. The allocation was later reassigned to the San Francisco-Oakland-San Jose television market; Stockton, meanwhile, became part of the Sacramento television market.

The current station on channel 36 first signed on the air on October 9, 1967 as KGSC-TV; it is currently the longest continuously operating commercial UHF television station in the Bay Area. KGSC was notable for its all-night movie presentations, which were hosted for several years by the "Old Sourdough" and "Chief Wachikanoka".[1] While there were several sets of hosts for the all-night movies, including Eugene Hogan, an experienced emcee who was best known for his work at San Jose radio station KLOK (1170 AM), most versions were branded as Movies 'Til Dawn, and sponsored by local retailer MMM Carpets.

During the 1970s, the station promoted itself as "The Perfect 36" and employed busty San Francisco stripper/entertainer Carol Doda as its spokesmodel. KGSC was purchased by Ralph Wilson in 1981 and changed its call letters to KICU. The station identifications that were used by the station after the callsign change featured a breathy, husky voiceover by Doda reading: "I see you, San Francisco. You're watching the perfect 36 ... KICU, San Jose." In addition to breathing the station IDs, Doda would also perform the station's editorials, which like the IDs were laced with double entendres. The first take was always broadcast, with any mistakes included.[2] Over the years, the station ran a number of drama series and older movies. It added more classic sitcoms and children's programs by the mid-1990s. However, the station gradually phased out children's programs from its schedule between 1998 and 2002.

The station was sold to the Cox Broadcasting (now Cox Media Group) subsidiary of Cox Enterprises on November 28, 1999, creating the first television duopoly in the San Francisco Bay Area with KTVU once the deal was finalized in early 2000;[3] KICU subsequently moved its operations from its original San Jose studios and integrated them with KTVU at that station's facility in Oakland's Jack London Square.

On June 24, 2014, Fox Television Stations announced that it would acquire KTVU and KICU in a trade deal in which the company's Fox owned-and-operated stations in Boston, Massachusetts (WFXT) and Memphis, Tennessee (WHBQ-TV) would be swapped to the Cox Media Group.[4][5] The trade was completed on October 8, 2014.[6] There is a possibility that KICU would become an owned-and-operated station of the co-owned MyNetworkTV programming service under Fox ownership, either after the service's current affiliation agreement with KRON-TV (channel 4) expires (similar to the situation in Charlotte in which Fox Television Stations purchased WJZY and nullified its affiliation agreement with charter Fox affiliate WCCB), is given up voluntarily, or is moved to KICU at some point before KRON's agreement with MyNetworkTV lapses.

When KTVU's website was moved to Fox's preferred WorldNow platform, KICU's site was also removed entirely, with Fox reducing the station's web presence to a bare-minimum page on the new KTVU site, which features television listings, FCC-required disclosures and forms of contact, and the default TMZ on TV video portal.

KTVU operates its Mobile DTV feed of subchannel 2.1 (labelled "KTVU MB") over KICU-TV's digital signal, broadcasting at 1.83 Mbit/s, though KTVU has plans to move the Mobile DTV feed to its own signal.[8][9]

KICU-TV shut down its analog signal, over UHF channel 36, on June 12, 2009, the official date in which full-power television stations in the United States transitioned from analog to digital broadcasts under federal mandate. The station's digital signal relocated from its pre-transition UHF channel 52, which was among the high band UHF channels (52-69) that were removed from broadcasting use as a result of the transition, to its former analog-era UHF channel 36 for post-transition operations.[10]

Occasionally as time permits, KICU may air Fox network programs whenever KTVU is unable to in the event that channel 2 must air extended breaking news coverage or because of conflicts with other locally produced special programming on that station; this was also the case when KTVU aired San Francisco Giants baseball games that ran into or aired during primetime hours, until it lost the broadcast television rights to the Giants to NBCowned-and-operated stationKNTV (channel 11) in 2007. With KNTV becoming the broadcast home of the Giants in 2008, KICU took on the role of airing pre-empted NBC programming in lieu of KNTV. In 2010, KRON-TV (channel 4) – NBC's original Bay Area affiliate until the network's programming moved to KNTV in January 2002 due to a dispute between the network and KRON's now-former owner Young Broadcasting (which has since merged with Media General) – took over the duties of running NBC programs preempted by KNTV. The duty of being NBC's backup affiliate in the Bay Area in the event that KNTV broadcasts Giants games and breaking news coverage was turned back over to KICU in 2012.

KICU served as the broadcast television flagship for Oakland AthleticsMajor League Baseball games until 2009, when the A's signed an exclusive television deal with regional sports networkComcast SportsNet California. Since KTVU had rights to the Giants, the Cox duopoly essentially had exclusive control of the local broadcast television rights to both of the Bay Area's MLB teams for a short while until channel 2 lost the rights to the Giants at the end of the 2007 season to KNTV.

In 1995, KICU obtained the broadcast rights to carry Golden State WarriorsNBA games; the station aired several Warriors games each season until the 1999-2000 season, after which it lost the rights to regional sports networkFox Sports Net Bay Area. The station also was a longtime broadcaster of NHL hockey games featuring the San Jose Sharks. Until the program's cancellation in 2008, the station also aired the sports highlight program High School Sports Focus on Friday nights at 11:00 p.m. (which was rebroadcast on Sundays at 4:00 p.m.); the program won several Regional Emmy Awards.

KTVU presently produces 2½ hours of locally produced newscasts each week for KICU (with a half-hour on weekdays); KICU does not carry newscasts on Saturdays and Sundays. In addition, the station airs the KTVU-produced programBay Area People, which is rebroadcast Sundays at 9:00 a.m.

KICU produced a half-hour evening newscast during the 1980s and 1990s, which originally aired at 7:30 p.m., but was eventually moved to 10:00 p.m., placing it in direct competition with eventual sister station KTVU's higher-rated primetime newscast. Jan Hutchins (formerly a sportscaster at KPIX) was a longtime anchor of the program, along with Ysabel Duron; reporters included Bill Buckmaster, Tony Russomanno and Melanie Morgan. KICU also ran Independent Network News, a syndicated nightly news program produced by then-fellow independent station WPIX in New York City, at 10:30 p.m. from the late 1980s until the program's June 1990 cancellation. KICU revived its news department in 1992, with the launch of a nightly early evening local newscast at 7:00 p.m. called Action 36 Prime News, this program was cancelled in 1994.

After being acquired by Cox Enterprises, KICU began airing a rebroadcast of sister station KTVU's primetime newscast The Ten O'Clock News each night at 11:00 p.m. from January 2000 to September 14, 2001, under the title The Eleven O'Clock Edition of the Original Ten O'Clock News (the "Original" branding was used to stand out from 10:00 p.m. newscasts that aired a few years prior on KRON-TV and CBS station KPIX-TV (channel 5) – both of which pushed their network primetime schedules back an hour in order to improve viewership and to compete with KTVU – as well as a KNTV-produced program that aired on KBWB-TV (channel 20, now KOFY-TV) at the time). KICU also aired a simulcast of the 7:00 to 9:00 a.m. block of KTVU's Mornings on 2 newscast during the early 2000s, with a ticker featuring traffic and weather information, news briefs and breaking news stories specific to the South Bay area. The station resumed airing a newscast on January 21, 2008 with the launch of Bay Area News at 7 on TV 36, a half-hour weeknight 7:00 p.m. newscast that is produced by KTVU.[11] On April 5, 2010, KICU restored a rebroadcast of KTVU's 10:00 p.m. newscast to its schedule, this time at 11:30 p.m. each weeknight. The rebroadcast of The Ten O'Clock News was moved back to the 11:00 p.m. slot it held during its original run on KICU on July 1, 2013.